Secretions from human, such as sweat, tears and sebum, cause makeup to run. Particularly, for sunscreen agents and make-up cosmetics, secretion such as sebum from a skin, besides oil blended in the cosmetics, excessively wet powder in cosmetics. This is a major factor for the makeup to run. Further, friction is one of external factors of the makeup to run. Therefore, the surface of powder is hydrophobized with a reactive silicone, a silane coupling agent or a fluorine compound to improve water- and oil-repellency of the powder, whereby durability of cosmetics is improved.
An oil mixture of silicone oils, hydrocarbon oils, ester oils and glyceride oils is often used as an oil agent for cosmetics containing powder in order to improve its feel or compatibility with other components. Further, a highly polar organic ultraviolet absorbent is contained in cosmetics having an ultraviolet absorbing effect. Then, the cosmetics have worse uniformity as a whole of solution or dispersion and, accordingly, worse stability with time, such that the oils separate or powder settles.
In order to solve the aforesaid problems, Patent Literature 1 describes a cosmetic comprising an alkyl-modified organopolysiloxanes having a long alkyl chain, and methyl trimethicone. Patent Literature 2 describes a cosmetic comprising a silicone having a long chain alkyl group and a polyoxyethylene group. In these cosmetics, the oil component is stably suspended, but the powder is not enough stably suspended.
Patent Literature 3 describes a make-up cosmetic comprising modified powder obtained by coating the surface of powder with methyl hydrogen polysiloxane and heating the powder. However, when the methylhydrogenpolysiloxane type surface treating agent, such as methylhydrogenpolysiloxane and dimethylmethylhydrogenpolysiloxane is adopted, unreacted Si—H groups remain on the surface of the powder. Accordingly, when the powder is added in a cosmetic, there is a problem that hydrogen gas generates, depending on a property of liquid. Patent Literature 4 describes a cosmetic comprising pigments treated with an organic silicon compound, wherein a one-terminal alkoxy-modified linear silicone is orientation-adsorbed on the surface of the pigment and heat treated. However, the one-terminal alkoxy-modified silicone has less points reactive with powder, compared to the methylhydrogenpolysiloxane type treating agent, so that untreated surface remains in the powder. Therefore, when the powder treated with the one-terminal alkoxy-modified silicone is used in a pressed powder cosmetic, the treatment effect is not sufficiently obtained in a solution system.
Further, Patent Literature 5 describes powder surface-treated with an acrylic/silicone copolymer having a hydrolyzable silyl group. Patent Literature 6 describes a silicone treating agent for powder which has a silicone chain having a branched structure and a hydrolyzable alkoxy group. Patent Literature 7 describes a water-repellent cosmetic powder obtained by treating powder with a carboxyl group-containing organopolysiloxane. These surface-treated powders have excellent water- and oil-repellency. However, when these powders are used in a cosmetic comprising a highly polar oil, such as an ester oil and an organic ultraviolet absorbent, there are problems such that the powder settles with time, color of a coating film is uneven and a color irregularity occurs and, therefore, these powders are not satisfactory.